Hydraulic clutch shifting mechanism



Feb. 7, 1939.k E. Q SCHJQUN 2,146,031

HYDRAULIC CLUTCH SHIFTING MECHANISM loriginal Filed July 1, 19.36 2 sheets-sheet 1 v/ Sito: um.

Feb; 7, 1939. E. o. SCHJOLIN HYDRULICCLUTCH SHIFTING MECHANISM Original Filed Julyl, 1936 2 Shets-Sheet 2 mmltor .ja/mf (Ittornegs Patented Feb. 7, 1939 PATENT Aor-'r-'lcr-z HYDRAULIC CLUTCH SHII'TING HEUHANISH Eric 011e Schiolin, Pontiac, Mich., signor to General Motors Corporation, Detroit, Mich., a corporation of Delaware Original application July Al, 1936, Serial No. 83,318.

Divided and this application June 19, 1037, Bc-

' rlal No. 149,947

Minimi.v (cl. 1oz-s1) This invention relates to automotive vehicles and has particular reference to means for operating the clutch associated with an internal combustion engine and change transmission all posi- 5 tioned at the rear of the vehicle. This application is a division of my copending application Serial No. 88,318, led July 1, 1936.

In thepresent practice where the engine is positioned at the front of the vehicle, the matter of operating the controls such as the shifting of the gears of transmission or 4of disengaging the clutch has oirered no serious problem. However, where the engine, the clutch and the transmission are positioned at the rear of the vehicle, or I specilcally, over the rear axle, and the controls or operating levers are -at the iront seat where they are accessible tothe driver, the problems are more diiiicult.v Where the transmission is at the rear of thevehicle, it has been found that it is desirable to make a more compact construction, particularly in the case of light vehicles where the engine Ablock and transmission housing are cast as a unit. In thepresent invention, the transmission is positioned in'a direction transversely of the vehicle instead of longitudinally as in prior practice, and this transverse positioning oiiered additional problems.

The transmission associated with the invention is of the usual gear type having one shiftable gear to operate the vtransmission in low and reverse, and a' second shiitable gear to cause the transmission'to operate in second and high. The two shiitable gears are operated by the usual forks which are operated from concentric tubes posi- 35 tioned in a housing orbox fastened to the side of the transmission housing. The operating tubes project downwardly out of the ybox and have attached at their ends arms which in turn are connected by metal ribbons to the shifter means for 4 the transmission as. described in my original api plication. The ribbonsare passed from the rear tothefront through grooves in the floor board, the grooves being covered by metal strips to main- 45- tain a level and rigid door.

The clutchis operated hydraulically, that is.

the usual clutch pedal is connectedto -a hydraulic cylinder which transmits fluid pressure to the rear lof -the vehicle to operate the shifter rod for 50 the clutch.

Figures 3 and 5 are sectional views on the corresponding lines of Figure 2.

Figure 4 is a sectional view on the line 4`4 oi' Figure 3.

Figure 6 is a detailed view partly in section 5 showing the bleed opening for the hydraulic cylinder.

Figure 'I is a plan view of the clutch mechanism but showing a mechanical way of operating the clutch shifter rod. 1

Instead oi the mechanical operation of the clutch by means of a ribbon, levers and a tube, the clutch shifter rod I13'- may bel operated hydraulically. The manner in which this is accomf plished is shown in Figures 1-5 inclusive. The 15 receptacle 2i2. A spring 2i4 between the piston 25 and the end oi the cylinder constantly urges the piston to the position shown in Figure 1. A suitable iiexible boot 2I6 is secured in liquid tight relation to the link 206 and to the end of the cylinder 2I0 to prevent the entrance of moisture 30 and dirt. 'Ihe receptacle 2I2 has the feet 2l'l by means of which it is mounted on a plate 2I8 secured to any suitable part of the vehicle. The cylinder has the small bleed opening 220 to allow a small amount of fluid to ilow into the cylinder 35 from the receptacle 2i2 when the parts are in the position shown in Figure l. T'his will allow the replacement of any iiuid which may be lost through leakage.

A tube 222 leads from the endof the cylinder 40 2I0 to a iitting 224 secured to the box 92 which in turn is mounted on the transmission housing in the same manner as the box 92 in the parent application. A part of the transmission shifting mechanism is shown at 66 and |24. 'I'he fitting 45 is hollow and has the tube 226 passing therethrough. 'I'he tube is threaded at its extremity and has threaded thereon the nut 226, the purpose of which is vto hold the tube 226 and the iitting. 224 rigidly in place. The iltting 224 is 60 soldered to the tube 226 as indicated at 230. The

fitting 224 is hollow and communicates with the tube 226 by means of the openings 23|.V

The tubel 226 vhas a head 240 formed at its extremity, the head 24| projection into the trans- 55 mission housing 24 and has a fiat face 242 which abuts against a corresponding fiat face 244 formed in the transmission housing around the v passage |88 which receives one end member 245 of a clutch shifter rod |18'. The shifterrod |18' comprises theend member 248, the second end member 248 and the cylinderv 258. The head 242 is additionally provided with an extension 252 which fits inside the bearing passage |88.

The head 248 has a tubular extension 254 projecting from one side and secured adjacent the end of this extension is a piston 255. The piston 255 has an inner flange 259 resting on a shoulder 258.0n extension 254. A second shoulder 252 on the extension aids in supporting a rubbercup 254 which closely ilts the interior of the cylinder 258. 'I'he extension 254 is bored as shown at 255 and communicates with the bore of the tube 228 so that the liquid coming through the pipe 222 will be transmitted through the tube 225 and the bore 255 to the end of the cylinder 258. Inasmuch as the piston 258 is stationary; the forcing of liquid intothe system will cause the cylinder 258 and its connected end parts 245 and 248 to move downward when considering Figure 2. This will cause the movement of the clutch shifter rail |18' to disengage the clutch 25.

The cylinder 258 has a threaded stub extension 258 which is screw threaded into the member 248 of the shifter rail |18'.

Inside the cylinder 258 a boot 218 is provided. The boot is secured at one end against the piston 255 and its other extremity is pressed tightly against the other end ofthe cylinder andthereby prevents the entrance of dirt and moisture into the cylinder.

Referring to Figures 3 and 4, there is here shown the manner in which the cylinder 258is connected to the element 245 of the shifter rail |18'. The shifter rail has its end forked as shown at 212, there being received between the fork, the head 248 of the tube 225. At the extremities of the fork 212 notches 214 are provided land the cylinder 258 is provided with openings 215 and 218 which mate or conform with the notches 214. A U-shaped iron 288 is passed through the openings 215 and 215-and is received therebetween inv the recesses 214 and rigidly connects the cylinder 258 with the element 245. A wire 219 passing through an opening 28| in the end of the U iron 288 holds the iron in place.

In Figures 5 and 6 there is shown the manner in which the air is emptied from ,the system in order properly to cause the hydraulic mechanism to operate.- The cylinder 258 has apassage 284 formed thereon which connects with a passage 285 formed in a projection 288 ksecured to the cylinder. The passage 255 in turn connects with the passage 298 which is shown in Figure 6 as closed by a plug 292 screw threaded in the end of the passage. When a system is originally installed the plug 292 is unscrewed so that the passage 298 is in communication with the opening 284 therein, the passage 294 communicating with the atmosphere through thev hollow plug 292. The operator reciprocates with the clutch pedal 28 a number of times until all of the air is expelled and there commences to come from the plug the liquid of the hydraulic system. When the liquid flows in a sufllcient quantity to' indicate that all of the air is expelled from the system, the plug 292 is tightly screwed in place to cause the opening 294 tightly to seat against its seat as shown in Figure 6 and prevent a further auaosi escape of liquid. The system is now filled with liquid and ready to operate.

The housing 82- is provided with a screw threaded plug 298 to allow access to the plug 282.

The hydraulic operation of the clutch has the advantage of being unaffected by relative movement between the engine and body. A short lengthflexible tubing may be placed in the pipe line 222 at the fixture 224 and this tubing wil take care of all relative movement.

In Figure 'I there is shown some of the structure of the basic application Ser. No. 88,318. This structure is to illustrate the connection of the clutch with the clutch operator rod |18 of :Figure 2. y

Referring to Figure 7-,-it will be noted that the transmission in the housing 24 is operated by ribbons I4 which comprise an outer pair 94a and an inner pair 84D. -The pair 54a are connected at their front to the ends of alever 44 pivoted at its center in the ball bearing on a shaft 48.

AThe pair of ribbons 54h are connected at thefront end to the ends of a shorter lever 58 pivoted at its center in a ball bearing likewise mounted on the shaft 48. In the neutral position of the transmission, the levers 44"and 58 are positioned over each other as shown in Figure 7. Y

The shaft 48 is mounted in a base plate 55 secured to the floor of the vehicle in any suitable way. The base 58 has mounted therein thegear shift lever of which the lower end 15 only is indicated. The end 15 is rounded and is adapted to be` shifted to be received in either the yoke 18 on the lever 44 or the yoke 88 on the lever 58. In the position of the lever end 15 as shown in Figure 1, it is incapable of. moving either of the levers 44 or 58 because it is in engagement with the fingers of the usual H slot in which the shift lever operates. By shifting the lever in the plane of the paper, either to the right or to the left, the end 15 may be caused to be engaged in either of the yokes 18 or 88 and also remove the shank of the lever into the open side of the H slot so that the lever may now be moved to swing-either the lever 44 or the lever 58 depending on whether the end 15 has 'been shifted intothe right or left slot. The swinging of the lever 44 for example,

vwill cause the movement of the ribbons 94a to shift the gears of the transmission 24.

The rear ends of the ribbons 54a are connected at 84 to the extremity of an arm 85 which in turn is secured at its middle to a tube or rod 98 which extends vertically upward in a housing er bex sz secured by means of the bolts to the The ribbon 58 to operate the clutch 25 from the pedal 28 is attached at its rear end as at |52 to a lever |54. end to a third tube |58 which has its Ilower end mounted in a bearing positioned in the lower extremity of the box 92 and its upper end mounted in a second bearing mounted in a partition in the box 92. The upper extremity of the tube |58 has secured thereto a hub |58 of a lever. |18, the end |12 of which is received in ya notch |14 fgmle'd. in a hub |15 secured to the clutch shifter r l The clutch shifter rail |18 is shown as extending a considerable distance in the transmission housing and at its end has pivotally secured thereto the clutch shifter fork |86. This fork is fulcrumed on a pin |81 and has the tooth |88 which presses against the plate |95) to compress a plurality of Belleville washers |92. When the clutch pedal is depressed the lever end attached to the shifter rod |18 will pull the lever downwardly when considering Figure 'l to compress the Belleville washers and move a quill shaft to shift the shiftable member |96 of the clutch 26. The clutch and its operation is better shown and described in my U. S. Patent No. 2,096,979.

I claim:

1. In a hydraulic means for shifting a shifter rail to operate a clutch, means to journal the rail in a transmission housing of an automotive vehicle, a cylinder formed in said rail, a stationary piston in said cylinder, a passage in the piston to enable liquid to pass from one side of the piston to the other, means to force liquid from one side of the piston to the other to cause the movement of the cylinder and the consequent shifting of the rail to operate the clutch.

2. In a hydraulic means for shifting the shifter rail to operate Athe clutch associated with the engine and transmission of an automotive vehicle, said engine and clutch being positioned at the rear of the vehicle, a lever at the front of the vehicle operating a means to transmit liquid pressure, a pipe to carry the liquid to the rear of the vehicle, a slidable rail mounted in the transmission housing, a cylinder formed in said rail, y

a stationary pistonin said cylinder, a passage in said piston to enable the liquid from the pipe to be passed from one side of the piston-to the other, the forcing of the liquid from one side of the piston to the other causing the movement of the cylinder and rail to cause the shifting of the clutch.

3. In a hydraulic means for operating a clutch, a shifter rail comprising two end pieces and an intermediate cylinder rigidly interconnected, means to mount the shifter rail slidably, a stationary piston in the cylinder, and means in the piston to enable liquid to be transmitted from one side thereof to the other to cause the cylinder to be moved overthe piston.

hicle, a clutch shifter rail slidably mounted in the transmission housing, a hollow intermediate part in said shifter rail, a piston in said hollowv part, means to transmit fluid into the hollow part through the piston to cause pressure to be exerted on oneside of the piston to move the hollow part, and means at the front of the vehicle operable from the drivers seat to cause the fluid to move into the hollow part to operate the clutch shifter rail.

5. In a hydraulic means for shifting the clutch of an automotive vehicle having an engine and a tranmission housing at the rear of the vehicle, a clutch shifter rail slidably mounted in the transmission housing, a head secured in the housing and over which the rail is slidable, a piston rigidly secured to said head, said piston and head being stationary, a cylinder surrounding the piston and forming a part of the rail, a passage in the head and pistonto enable fluid to pass into the cylinder and force the cylinder and rail to move relative to the piston to cause the movement of the rail and the operation of the clutch,

and means at the front of the vehicle to transmit the hydraulic pressure to the head at the rear of the vehicle.

6. In a hydraulic means for shifting the clutch of an automotive vehicle having an engine positioned at the rear thereof, a clutch shifter rail slidably mounted at the rear of the vehicle, a cylinder embodied in said rail, a head rigidly mounted at the rear of the vehicle and over which the shifter rail is adapted to slide, an extension on the head, a piston on the extension, said cylinder surrounding said piston, means at the front of the vehicle operable to transmit hydraulic pressure to the rear of the vehicle, and a passage connected to said means and extending through the head, the extension, and the piston and adapted to deliver fluid between the piston and the cylinder to cause the movement of the cylinder to move the shifter rail to shift the clutch.

ERIC OLLE SCHJOLIN. 

